This project examines neurobiological responses to training and to post-training manipulations that modulate memory processing. In large part, these experiments attempt to determine whether hormonal responses to training modulate (i.e., enhance or impair) memory processing by acting on central biogenic amine systems, and whether these agents do so by acting on central noradrenergic systems. The research in this project will determine: 1) whether retrograde memory enhancement and amnesia produced by most classes of treatments can be attenuated by adrenergic receptor blocking agents, and whether these anatogonists exhibit this effect because of central or peripheral actions; 2) whether amphetamine, ACTH, and subseizure amygdala stimulation, each a treatment that modulates memory processing, result in a post-training change in brain noradrenergic activity that predicts later retention performance; 3) whether other neurobiological measures, e.g., 2-deoxyglucose uptake by the brain, are sensitive to training-related stress and if the response is altered by post-trial memory modulating treatments in a manner that is correlated with retention performance of learned responses.